Generally, electrostatic discharge (ESD) is the transfer of an electrostatic charge between bodies at different electrostatic potentials (voltages), caused by direct contact or induced by an electrostatic field. In the electronics field, as internal structures and electronic components in integrated circuits continue to get smaller, it is becoming easier to destroy or otherwise impair integrated circuits through the discharge of static electricity. ESD has become a critical problem for the electronics industry, and it is desirable to develop new types of protection circuits.